Problem: If $\mathbf{a}$ and $\mathbf{b}$ are vectors such that $\|\mathbf{a}\| = 7$ and $\|\mathbf{b}\| = 11$, then find all possible values of $\mathbf{a} \cdot \mathbf{b}$.

Submit your answer in interval notation.
Solution: We know that $\mathbf{a}\cdot\mathbf{b}=\|\mathbf{a}\|\cdot\|\mathbf{b}\|\cdot\cos \theta =7\cdot 11\cdot\cos \theta$, where $\theta$ is the angle between $\mathbf{a}$ and $\mathbf{b}$. The range of values of $\cos \theta$ is $[-1,1]$, so the range of values of $\mathbf{a}\cdot\mathbf{b}$ is $\boxed{[-77,77]}$.